Timeline
From Sonic Retro
| Prototypes within this group may not be in correct order. They may be even from one prototype. |
Sega Visions '92 M09 |
Nick Arcade T01 |
Sonic 2 Proto v1.54 "Wai" Proto |
Mean Machines Sega VHS T02 |
GamePro M02 M05  M06  M20  M21M22  M23 M24 |
Spanish Promotion VHS T03 |
MegaForce '92 M14  M15  M16  M17 |
Sega Sonic Gold Guide '93 M10  M11  M12  M13 |
Sonic 2 Manual M08 |
Unknown French media M07  M18  M19 |
Sonic 2 Final Final | |
| TIME | -> | -> | -> | -> | -> | -> | -> | -> | -> | -> | - |
|---|---|---|---|---|---|---|---|---|---|---|---|
| EHZ snails | - | Y | Y | - | - | N | - | - | - | - | N |
| CPZ loop full corners | - | - | N | N | - | N | - | - | - | - | Y |
| CPZ crossbar tile | - | Short | Tall | Tall | - | Tall | Tall | - | - | - | Tall |
| Title cards | - | - | Silver | Silver | - | Silver | - | - | - | - | Gold |
| Spindash dust | - | - | N | - | - | - | - | Y | - | - | Y |
| Sonic sprites | - | P | P | F | F | F | F | F | - | - | F |
| Tails can fly | - | - | N | Y | - | Y | Y | - | - | - | Y |
| Tails icon | - | - | 
|
|
|
|
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- | - | - | 
|
| 2P option | - | N | N | - | N | N | - | Y | Y | - | Y |
| Special Stage | - | - | N | - | - | - | - | - | - | Y | Y |
| Boss landing | - | - | | | | | - | - | | | - | - | - | / |
| Boss defeated facing* | - | - | L | - | - | R | - | - | - | - | L |
| Boss flyaway facing** | - | - | L | - | - | R | - | - | - | - | R |
| Boss explosion | - | - | N | - | Y | Y | - | - | - | - | Y |
| Boss burnt | - | - | N | - | - | N | - | - | - | - | Y |
* When EHZ boss is facing left as it takes the final hit, which way does he face after defeated?
** When EHZ boss is facing left as it takes the final hit, which way does his aircraft face as he escapes to the right?